"Ooooh" I said as I was reading Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of all Ages. I had opened the book to the Stegosaurus account and my eyes were drawn to a caption for an illustration depicting a Stegosaurus thrashing at a Tyrannosaur type meat eating dinosaur with it's spiked tail. The caption stated "The thagomizer of Stegosaurus provided a powerful defense...."
I thought "that's a curious word - thagomizer. I wonder where that came from?"
A little searching through the text found that it indeed was a curious word with an even more interesting etymology. It turns out that the Thagomizer was named after the late Thag Simmons. Who was Thag Simmons? It appears that, according to a good source, Thag Simmons was an unfortunate pre-historic human who first discovered the dangers of a Stegosaurus tail first hand. OK you say, now this is getting weird. Everyone knows that dinosaurs and any sort of pre-historic human did not exist during the same time! Would it help if I told you my source was Gary Larson?
Apparently paleontologist Ken Carpenter thought the thagomizer was a good name for the business end of the Stegosaurus tail and he used the term in a 1993 presentation in which he described the most complete Stegosaurus ever found. However, Ken may have originally been joking a bit. He did not use thagomizer to describe the Stegosaurus tail in a subsequent paper (Carpenter 1998) describing what was probably the same specimen but the book states that it is now accepted scientific nomenclature.
Here is the cartoon which I found at the Wikipedia site that describes the thagomizer and it's origins a bit more. This was too good to pass up.
So is the Dinosaur encyclopedia. I bought it for my son Benton's fifth birthday and he loves it (thanks to Darren at Tetrapod Zoology). I really like it too. It has great illustrations and I look forward to reading more, particularly on the Avialians (of course).
Carpenter, Ken. 1998. Amor of Stegosaurus stenops, and the taphonomic history of a new speciment from Garden Park, Colorado. Modern Geology 23:127-144.
"Now this end is called the thagomizer, after the late Thag Simmons."